The long-term objective of the proposed R21 effort is to reduce the cost and improve the quality of medical imaging, thereby improving detection, diagnosis, and therapy for a number of human health diseases. The specific aim of this research is to fabricate advanced high-resolution collimators for nuclear medicine imaging at a significantly lower cost than currently is possible. An innovative fabrication technology will be used to produce advanced high-resolution collimators made from an improved material (tungsten powder composite). The combination of a new fabrication method and new collimator materials offer important advantages in terms of design flexibility and performance over current collimator fabrication techniques. This is an enabling technology. Most importantly, it has the potential to allow very high-performance collimators to be produced at a relatively low cost. The proposed exploratory effort will demonstrate technical feasibility by fabricating prototype low energy high-resolution (LEHR) collimators employing a dense (approximately 11 g/cc) composite material, and comparing their dimensional accuracy and imaging performance against state-of-the-art LEHR collimators commercially available. Potential commercial applications include nuclear medicine (small and large format cameras), computed tomography, mammography, as well as non-medical applications such as astrophysics, non-destructive testing, and security scanners.